


Give and Take

by TheProtobabe



Category: Undertale (Video Game)
Genre: Aftercare, Aggressive Sans, BDSM, Biting, Choking, Cunnilingus, Dirty Talk, Dom!Sans, Domination/submission, Ecto-Penis (Undertale), Established Relationship, F/M, Fellatio, Female G-Spot, Fluff, Gravity Magic, Hair Pulling, Multiple Orgasms, Pain/Pleasure, Penetration, Possessive Sans, Reader Gender Unspecified, Reader has a vagina, Restraint, Soul stuff, Tentacles, breath play
Language: English
Status: Completed
Published: 2016-09-20
Updated: 2016-09-20
Packaged: 2018-08-16 09:54:12
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,757
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8097634
Author URL: https://archiveofourown.org/users/TheProtobabe/pseuds/TheProtobabe
Summary: Sans needs to know that you still belong to him, that you still want to give yourself to him. So, you do. And he takes everything you give.





	

**Author's Note:**

> Mind the tags, folks.

 

It’s late, and he still hasn’t come home. You tuck your knees in under your chin, holding your phone and waiting for a text back. You’re worried, but you don’t want to panic until it’s been a little while longer. As it is, you’re still angry, and you would let him know that the _second_ he walked in.

Then the door creaks, and you let out a huge sigh of relief, and you get up-- _’No, you’re angry! Stay mad,’_ you remind yourself, and you go to make your way downstairs.

“Babe.”

His voice is behind you and you whip around. The feeling twists quickly into indignation, but then right back to worry when you catch the look in his eye. Something is wrong.

“...Sans? Is everything…?”

He interrupts you by popping forward with magic, surging into you and closing you off with the cage of his arms. He’s kissing you, tongue delving into your mouth greedily, desperately, hand wandering down to your hip to slip under the oversized tee you were wearing. You let out a squeak of surprise, relaxing into the heady feeling. But then stiffen and push him away, searching his face carefully.

“Sans. You taste like alcohol,” you tell him, frowning. He’s staring at you through half-lidded eyes, face flushed. It’s honestly incredibly enticing, but now you knew something was _off_. Something had happened and he felt he needed to stop by Grillby’s before coming home.

He looks as if he’s just going to dive in and kiss you again, but he hesitates just before his mouth meets yours and he lays his forehead on your shoulder. Automatically, your arms go around him and surround him with comfort.

“Baby? C’mon, tell me what’s wrong,” you insist, voice rising in octave. This was very uncharacteristic of him; he was so closed off, most of the time, never letting you in on his emotions when he was having a bad day. So the fact that he was accepting comfort was… alarming, to say the least.

A few ticks of silence passed before he speaks. “I can’t… I just want…” he starts, but peters off. He pushes off to look you in the face, the pinpricks of light flicking between each of your eyes. “This is mine. You are _mine_ ,” he growls, and his fingers dig divots into your flesh.

He says it in a way that is commanding, and you open your mouth to protest that no, you don’t _belong_ to anyone, but… you hesitate at the look on his face. There’s something there that _needs_ to hear the right answer, something desperate. He says your name and there’s a strange edge to his voice that tells you he’s saying something with a much deeper meaning that you initially thought.

So, instead of denying him, you answer what he’s really asking by taking his hand, putting it at the spot between your breasts, and nodding.

“Yes,” you breathe, not breaking eye contact. His posture sags slightly, for just a split second, before he’s surging forward again, tongue in your mouth and taking, taking, taking. He tastes a little like rum, you think, but a strange pressure catches your chest and you’re suddenly weightless, being pressed up against the wall, and his eye is flaring bright blue and his mouth is parted so his fangs show and right now he really looks _monstrous--_

“You remember what to say if you want me to stop,” he tells you. It’s not a question, but you nod anyway. He’s never used his magic on you, and frankly it’s a little bit scary. But he’ll stop if you ask him; he always does. So, you trust this, even if it’s something new.

“Wait, Sans, you’re… you’ve been drinking?” you hedge as he closes in on you. He tilts his head at you questioningly. He doesn’t seem as though he’s overly inebriated, but… “I don’t… want you to do anything you wouldn’t want to do sober,” you explain, tilting your face away. You feel his fingers catch your chin and turn you towards him.

“I only had a couple. Was gonna…” he trails off, eyes looking down at his thumb as it catches your fleshy lower lip. “Decided to come home,” Sans answers, voice soft. He leans up to kiss you again, because you’re still against the wall and you’re just a touch higher up than normal. You automatically wrap your legs around his hips when he presses his body against you, and your arms drape over his shoulders. And he’s kissing you, sweetly this time, full of hesitancy and need and love and with every stroke of his tongue and with every little sound that escapes his mouth you want him. You want him _so_ badly, and then you realize what you said earlier. What it really means, and suddenly you want to belong to this man, to this _monster_. He senses the spike of emotion in your soul, and he’s panting against you and taking you in desperately--

You gasp when his magic presses into you again and scoots you higher up, and you’re forced to use his shoulders as leg rests. It takes a split second for you to realize the implications of this and you squeal in embarrassment.

“Easy, babe,” he teases, his bright pupils flicking up to take in your face. He turns, deliberately keeping eye contact, and bites at the inside of your thigh. You feel your skin flush, which only gets worse when he closes his eyes and takes a deep breath near your pussy. “God, I love your scent,” he growls, which makes you squirm until he bites your other thigh, harder this time.

“Ah! S-Sans, that’s,” you gasp, not sure if you were a fan of the sharp pain or not. He gives you a glance, flashing a sharp grin at you.

“Remember to use the safe word if I do somethin’ you don’t like,” he reminded. “But I got a feelin’ you might have a higher tolerance than you think. In fact,” he grabbed at your thigh, hard. It hurt, but it was also... “I think you _like_ this.” His voice was silky, dangerous.

You can feel the heat radiating off your cheeks at this point. “I, u-uh, I’ve never, tried this sort of thing? I don’t know if, um…” Were you into this kind of play? You’d never tried it with any of your partners before, but then again none of them were really interested in anything past vanilla sex, so...

He smirks up at you while you’re talking and removes a shoulder from under your thigh. You squeal in alarm until you realize that you’re not going anywhere--his magic has you firmly planted against the wall. It’s almost as if the wall has become the floor, like the direction of your gravity has been completely _altered_.

While you’re working this out in your head, Sans has hooked his bony fingers beneath the band of your underwear and slid them off. They weren’t your cutest pair, but he doesn’t seem to mind that at all, and replaces the spot under your leg with his shoulder again. His face is close to your naked center and you’re stammering with something bordering arousal and nerves, but he only chuckles at you. You feel his hand wrapping around the outside of your thigh, moving you exactly where he wants you, and you see one of his canines glistening faintly before he dives into you all at once.

You aren’t really ready for that, and so the noise that comes out of you is one of complete surprise. It quickly turns into a low, needy moan as his tongue (dear lord that _tongue_ , it could get longer when he wanted and god it was changing shape inside of you right now holy shit) caressed at the inside of you. You reach forward to grab at the back of his skull, to control him. The fear of falling from your height is forgotten as your hips roll forward, but then your hands are moved away forcefully. Blinking, you wonder how he did this when his hands are still beneath your thighs, when suddenly both wrists are pinned at either side of your head without your permission.

Slow strokes of his tongue were distracting you, but you turn your head and look at your hand to see something blue and flickering with magic pinning it there. You swallow, licking your lips. You hadn’t realized Sans could do this. That he could do _any_ of this, really. You feel a little bit cornered, caged in and controlled at his whim, but… he did say you could stop him at any point, right?

Your twinge of uncertainty and fear was not lost on him. With a slow lick to the outside of your lips he backs away and grins wickedly up at you. “Didn’t know I could do that, huh?” he asks. You give him a look and he laughs. “I told ya. You’re mine, sweetheart.”

The pressure in your chest is back and it feels like someone has grabbed you and thrown you. Your back hits the bed and your wrists are still pinned, but now they’re both put together above your head. You try to sit up but the magic has you trapped there, right where he wants you. You look up at him as best you can and suddenly he seems as if he towers over you. His eye is flickering brightly, casting dancing shadows across the room and throwing his features into sharp relief. He is intimidating as all hell like this. He _frightens_ you a little. But holy _fuck_ was it turning you on.

“God, look at you,” he says. He gets onto the bed, his right knee between your legs. He hovers over you, his hot breath at your neck as he nips at it. “Maybe… two or three,” he mutters to himself. You turn your head slightly, brow furrowed in confusion.

“What? What are you talking about?” you ask, but he distracts you when a hand skirts along your belly and beneath your breast. It’s such a light touch that the sensation sends goosebumps up and down your arms. “Sans…” you huff.

“Mmm. I think…” He backs off, looking at you with interest. He raises his left hand and twists it in a funny way and you’re moving again, his magic just putting you there like you’re a ragdoll. You’re flipped over, hands rearranged to be behind your back and you’re face-down. “Yeah, I think this is where I want you.” He gets between your legs again, and now magic is pushing your knees forward until you’re exposed to him.

“Sans! This is… I--” Your face seems to not want to go back to its normal color tonight, because he keeps surprising you with how bold he is. “Jeez, you’re just gonna… ohhhh,” you breathe, because he’s dipped his fingers inside of you. You’re wet already, so he’s met with very little resistance.

“Remember what I said about telling me to stop,” he says, and this time it’s softer but you can sense something intense behind his words. And then you inhale sharply, because his hot breath is right at your center again, and you hardly have time to feel exposed and embarrassed in this position when his tongue is inside you again.

“Oh, oh god. Sans,” you choke out. His tongue is bottoming out inside you, filling you so completely that you struggle to get away from the intense feeling. He growls--you can feel the vibrations against your skin, and you shudder--and his magic is tightening its hold on you. His hands grip your thighs roughly and spread you wider so you are completely open to him. You’re repeating his name over and over again, feeling the tightly wound coil in your abdomen almost ready to spring. Your toes are curling, your breath catches, and you close your eyes. You’re so close…

But then he backs off, leaving you empty. You let out an embarrassing whine and he chuckles somewhere above you. It’s hard to turn your head to look at him when you don’t have your hands available to prop yourself up, but you manage to give him a glance over your shoulder. His grin gets wider at your expression. “I love gettin’ ya all worked up like this.” He’s got his knee between your legs again, his thigh bone pressing at your pussy through his shorts. Your eyelids flutter and you involuntarily grind back onto him, to his amusement. “Tell me what you want, sweetheart,” he says. You bite your lip, knowing what you want to say, but… it’s so hard! You’re just too shy to say it aloud, and you end up muttering the words into the mattress.

And then there’s a pain at your scalp and your body’s being yanked upright, Sans’s thigh still at your center and pressing even harder. You barely have time to gasp before his mouth is by your ear, bones creaking as they grip you by the roots of your hair. “Tell me so I can _fuckin’ hear it,_ ” he growls, low and commanding. Good god, he’s never been this… dominant before! But it’s… it’s doing something to you, waking up some part of you that you’d not been aware had been there before.

Still, the words won’t come and you stammer, blushing bright red. He pulls even harder so your back is arched almost painfully, and there’s the sensation of your scalp burning… “I… I want you to fuck me, _please_ , Sans,” you say, because you’re not sure if you want to feel anything more intense than this, and you know he’ll get it out of you either way. He lessens his hold on the roots of your hair but doesn’t let go, and kisses your neck.

“Very good, kitten.” There’s a shuffle of fabric and you feel the blunt edge of his dick play across your thigh and then press insistently at your center. “You likin’ this, babe?” he asks, his voice an octave lower. You lick your lips, almost too embarrassed to say that yes, you did. You were _loving_ this so far. But he was checking up on you, so you really needed to say it.

“Y-yeah,” you affirm, and his chest rumbles in an inaudible laugh. You can feel his soul burning and buzzing brightly at your back, where his chest was pressing into you. He slips inside you, hitching for just a moment when you catch at the wide part of his cock, and then he’s buried completely inside. You give a low moan at the feeling that pitches into a sharp cry when you feel his teeth at your neck, and he simultaneously snaps his hips forward. He’s bottomed out in you, hit so deep that it almost _hurts_ but instead it’s an ache that fills you and just feels so damn _good_.

His mouth is still by your neck, whispering things to you about how good you feel around his cock, how much he loves the way you taste, the sounds you make when he pleasures you. His fingers unwind from your scalp and move to wrap around your soft throat. There’s just a bit of pressure as he holds you in place, the other gripping at the spot where your hipbone juts out as he fucks you. But there’s something trailing across your hip and belly at the bottom hem of your shirt. At first your mind can’t comprehend these sensations when he’s fucking you with this amount of intensity, but you start to notice when whatever it is starts to tingle.

Your mind processes each of his hands, and the magic keeping you bound, and this new thing that is touching you feels nothing like bone. You bite back a gasp when whatever it is grips your breast and tweaks your nipple none too gently. “Sans! What is--ah!” You stop thinking altogether when another of whatever it is has snaked down to your clit. You could feel a soft buzz emanating from it and you knew that Sans was using more of his magic. You wanted to question exactly how much more he could do with it, but it was very hard to think about this when you were quickly being pulled close to the edge of an orgasm.

“I’m… g-gonna--”

He grips your throat a little harder, cutting off your sounds until it’s just guttural choking. “That’s it, that’s it, come on, sweetheart,” he urges. You try to shout his name, but it only comes out as a whisper. And then you tense against him, you’re so close, and then you feel his teeth bite down hard--

“Ggh…!” The most powerful orgasm you’d ever experienced courses through you, hard and hot. You can feel yourself rippling all around his cock, and if you could, you’d scream.

“Fuck! Shit, babe,” Sans curses, and his thrusts become erratic. The magic he’s been using on you is tightening its grip and you’re sure you’re going to have bruises in the morning. He grunts and you feel the heat of his magic fill your lower belly, joining you at the tail end of your orgasm. You ride out the last few waves of it and slump in his grasp as he releases your throat.

You’re panting, but after a few moments you speak. “Sans, baby, that was… that was amazing,” you comment, and he chuckles against you. He hasn’t let up on his magic yet.

“Sweetheart. That was just the first one,” he says, and you turn your head slightly to look at him from the corner of your eye.

“What?” you ask incredulously. “But…”

He releases his magical hold on you and you flop down onto the bed, startled. Your legs are made of jelly, but you turn your body to face him. He’s looking down at you with a strange gleam in his eye sockets.

“You want me to stop?” he asks you, his voice low. He’s got that intimidating look from before, and you have to say… it’s still getting to you. His eye flares, flickering between blue and yellow so fast that it almost looks like a bright green. There’s a bright light coming from his ribcage, shielded somewhat by the shirt he’s wearing, but then there are wisps of magic working their way around him. Individual strands, fluctuating and moving, like… smoke, trapped in glass. And they are flickering like his eye, casting varying shadows across the bedroom.

You had come to associate the word “monster” with people like Sans, like your friends you’ve met: Papyrus, Undyne, Mettaton. They were all good, each in their own amazing way, and you would trust any of them with your life.

Right now, however, Sans looked like the definition of “monster” you’d heard as a child. The stories of the beasts that would hide beneath your bed, the ones that would stalk you in a forest, waiting for their chance to devour you. The ones of things creeping in the night, with fangs dripping, hackles raised.

Your lover raises his left hand, the one crackling with magic, and you're dragged forward until you're upright and face-to-face with him. You realize you haven't answered his question as he stares into your eyes. Your mouth feels dry.

“No. I don’t want you to stop.”

The corners of his grin curl up. “Good. Take that shirt off,” he orders. With shaking hands, you obey, but you hardly get it over your head when he yanks it the rest of the way off of you impatiently. You feel  _things_ wrapping around your body and you give a little cry as they dump you on the floor at Sans’s feet. You try to stand up again, but gravity suddenly feels far too heavy and you can barely get up onto your knees.

His hand reaches down to grip his dick to adjust himself, and suddenly it’s right there in front of your face. “C’mere. Ya made a mess all over my cock when you came around it,” he said. You look up at him, eyes wide. You know what he’s getting at, and he grins down at you. “Mm, you know what I want, don’cha, kitten? C’mon then. I wanna see your beautiful little mouth wrapped around it,” he growls, and your thighs shake with the strength it takes not to collapse under the power of his voice.

You obey once more, because honestly you really like allowing him to have this power over you. You rest your hand on one of hip bones and lean in, the other hand tilting his erection so you have better access to it. He was right; it was a mess, slicked with your cum mingled with his. You close your eyes and brush your tongue across the head, reveling in the way you both taste on him. One of his hands pushes some of your hair from your face before he settles at the back of your head, fingers laced in the roots again.

“Look at me,” he commands. Your eyes snap open and readjust to the dim lighting accompanied with the glow of his magic, and you direct your gaze up at him. You can see through the bottom of his jaw, just a bit, and the way his head is angled down at you makes him look powerful. You’re moaning around his cock now, taking more of him in. You automatically go to close your eyes again, but he’s having none of that--he tightens his grip in your hair and growls at you. You remember that he’d told you to look at him, so you open your eyes and oblige his demand, even if it’s nerve-wracking to be doing while holding eye contact.

You pull back so you’re at the head of his dick and you let it sit on your tongue. You like the way he’s always reacted to this image of you, and you’re feeling excited about his new behavior tonight. He reacts, the flickering disc in his eye widening until it fills nearly the whole socket, and you feel his magic at your wrists again. He’s pulled your hands forward this time so they’re fixed in place, wrapped around his hips so you’re forced forward. Your mouth adjusts to accommodate more of his length as you shift, realizing now exactly why he’s put you in this position. And you recognize the smoky tendrils of his magic moving out of the corner of your eye before they’re at your thighs, shifting them further apart.

Something’s wrapped tightly around your belly and pressing at the front lower part of you, just below your belly button, and something else is working its way from the back of your thigh towards your center. You groan, low and long, when you feel it slip inside you, testing the waters. The feeling is similar to when his cock is inside you, but this is more… flexible, you think, and as it twists and moves inside you suddenly jump at a much more intense feeling than you were prepared for.

“There it is,” he says above you, and your wide eyes look up at him in shock. Oh, you know what he was looking for, all right, but up until right now you thought it was some kind of myth. But as his magic teases at that spot, you feel your legs quaking with effort to steady yourself. You need to lean more heavily on him as his magic works at you, and when something else wraps its way between your breasts and teases at your nipple, you can’t support your weight anymore and sag forward.

He takes advantage of this and pushes your head as far as he can down onto his cock. You squirm, your throat constricting and adjusting to him, and if it weren’t for the fact that you’d done this many times before you’d need to get him to stop. “Tap me with your hand if you want me to stop,” he says, as if he’s able to read your mind.

You’re nearly overwhelmed by everything going on at once. The magic delving deep inside your pussy is threatening to make you fall apart completely with each pass, and the pressure on your belly is only making it even more intense. The taste of your slick and his cum in your mouth, the scent of sex, the wet sounds of what you’re doing, the pricks of pain at your breast and the buildup of feeling coiling in your abdomen are bringing you to the edge of something much, much bigger than you’ve ever experienced in your life. It’s frightening and exhilarating all at once.

One more tendril of magic wraps its way around your neck and the light pressure sends you reeling. Sans feels you tensing and yanks himself out of your mouth, and you’re vaguely aware of the animalistic noises you’re making but mostly you are drowning in your orgasm, your whole body spasming out of your control. It’s so strong that it nearly hurts, you’re seeing stars and maybe a little fuzzy blackness at the edges of your vision. Your pussy is constricting and pulsing around his magic; you suck in a desperate breath with each one.

And then, something in your chest _pulls_.

Your soul is there in front of you right while you’re cumming and the colors are fluctuating across it wildly with all the intensity you’ve ever felt before. Sans has one hand wrapped around his dick and working it up and down erratically while the other reaches out, the lights of his eyes back to white and blown wide. He touches the edge of your soul, and gooseflesh ripples across your arms.

Everything you are experiencing crashes down upon him and his back bows with the sheer amount of _feeling_ you’re sharing with him, and he’s at his own orgasm too and your chest is covered in slick cum, you’re shuddering and grasping at him and he’s gasping for air, holding onto your soul like it’s a lifeline. He sinks to his knees and wraps his arms around you after bringing your soul between you, protected by both of your bodies. You’re trembling, sobbing, because it’s so much, _so much_ \--

He can feel the warmth radiating from your soul. You are exhausted, but you love him so, so much. He’s murmuring soft words to you, and you can’t understand them but you’re aware of him and his gentle touch. Tears are streaming down your face and you’re gasping for air between sobs, and he’s holding you close to him and stroking your hair. It’s grounding you a little as you come down from that high.

“You did so good, sweetheart. Shh, shh, I gotcha…” You collapse against him, grabbing at his shoulders with the weakness of a newborn kitten. Your breaths slowly but surely even out and he picks you up to place you on your bed. He lies down next to you and touches your face gently as the other hand returns your soul. “There you are. There you are. You doin’ all right, babe?” he asks.

You turn your body so you’re on your side and face him, exhaustion making your eyelids heavy. “Yeah…” you say, embarrassed to hear how hoarse you are. You’d screamed a lot during that last one, you guessed. The corner of his mouth turns up. He takes one of your hands and brings it to his mouth, pressing a kiss to it before placing it on the side of his face.

“Thank you,” he breathes, so quietly that you almost don’t hear it. You’re starting to doze off, but you smile at him and scoot close enough to press a kiss to the spot just below his eye socket.

“I love you. You’re amazing,” you say. Your eyelids droop but you see the way his face softens at this. He reaches out to tuck a stray strand of hair behind your ear, and then moves to lay a blanket over you.

“Sleep, sweetheart. You were so good. You did so good,” he praises. You still want to know what happened to make him do all this, but right now you knew he just needed it. You curl up against his broad chest, letting him put his arms around you, and you fall asleep to the soft hum in his bones. 

**Author's Note:**

> So, in my head, Sans is behaving this way because there are a few people (humans) in town who have seen him and Reader walking around together, obviously as a couple. They taunted him when he was alone at his place of work, where he couldn't do anything about them, saying that monsters like him are "stealing their women" (they assume woman because of Reader's bio sex) and proceed to say things they could do to Reader that Sans couldn't possibly do.
> 
> This stirs up some unpleasant feelings, of course, ending in this little oneshot. I hope y'all enjoyed the smut I wrote for my birthday. Happy birthday to meeee!!!


End file.
